Sanding disk alignment tool

ABSTRACT

A sanding disk alignment tool for aligning a sanding disk having a plurality of dust collection holes to a sander platen having a cooperative plurality of holes is disclosed with a method of use. The tool includes a base member having at least two pins sized and positioned for cooperative insertion into the pluralities of dust collection holes extending from a surface thereof. The method includes the steps of inserting the pins through two of the dust collection holes in the sanding disk from the abrasive side, bending the sanding disk around the tool, inserting the pins into through two of the plurality of dust collection holes in the sander platen and advancing the tool and disk to engage the platen. Once initially engaged to the platen, the bend in the disk is released and the sides of the disk are laid down onto the platen, after which the tool is removed.

CROSS-REFERENCE TO RELATED APPLICATION(S)

The present application derives priority from U.S. provisional application Ser. No. 61/641,100 filed May 1, 2012.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to the field of handheld power tools and, more specifically to a device for use in conjunction with a power sanding tool for proper alignment of the coated abrasive.

2. Description of the Background

Sanding, the process of smoothing and shaping a material surface by rubbing with an abrasive, has many applications in industrial production and finishing of materials such as wood, metal and fiberglass. Commonly done by hand with an abrasive coated paper or cloth (i.e., sandpaper), the process can be accelerated and the results improved with the use of handheld power tools that mount and move the sandpaper on the work surface. Power sanders are available in a wide variety of designs including palm sanders such as the random orbital sander which typically has a round sanding platen to which a sandpaper disc is removeably mounted by pressure sensitive adhesive (PSA) or hook-and-loop fastener. The platen P (see FIG. 4) is rotatably attached to an electric motor within the housing of the sander S at a central bearing which moves through a random orbital path so that no portion of the sanding disk follows the same path on the work surface more than once. The random orbit minimizes swirls and imperfections that can result by continuous repetition of the same motion of the sanding disk on the work surface. When the sanding disk is worn out it is easily removed from the platen and replaced by a new disk.

Random orbital sanders are very effective at removing material from the work surface and, by design, create a significant amount of dust in the process. Inhaling airborne sanding dust is unhealthy for the operator of the tool. Dust that remains on the work surface may damage the work surface and negatively impacts the effectiveness and lifespan of the abrasive disk. Consequently, many random orbit sanders are provided with a dust collection means that attempts to capture and remove the dust generated by the sanding process. A typical dust collection system has a pattern of holes through the platen and into a plenum within the tool housing that is negatively pressurized by an internal fan or by connection to an external vacuum source. A cooperative series of holes provided in the sanding disk allows ambient air to be drawn into the plenum as a result of the low internal pressure, pulling with it the sanding dust before the dust can become airborne or be ground against the work surface by the operation of the sander.

Power tool manufacturers typically market sanders having 5 inch, 6 inch or 7 inch platens and sanding disks of 5, 6 or 7 inches are readily available for use with the appropriate size sander. There is no universal pattern or design for the holes through the platens of various manufacturers although there are several common designs used by many such that replacement abrasive disks from a given manufacturer may commonly be used with sanders from any number of other manufacturers. Platen hole patterns may include from 5 to 9 holes (or more) typically evenly spaced radially at a predetermined distance from the center of the disk. A center hole may or may not be provided. For example, a common 8-hole pattern positions 8 holes on a circle 2½″ inches in diameter at 60 degree intervals on a five inch sanding disk. A sander having a platen of this design is depicted in FIG. 3.

It is vital that the holes of the sanding disk be properly aligned with those of the platen when applying a new disk because a misaligned disk will eliminate or greatly reduce the effectiveness of the dust collection system by fully or partially blocking the holes through the platen. Alignment of the disc on the platen is typically done manually by the operator and it difficult to get exactly right even with experience. New disks are often applied and removed several times before the operator is satisfied with the alignment of the holes, wasting time and rarely resulting in perfect alignment.

At least one attempt has been made to solve this alignment problem. U.S. Pat. No. 6,663,478 to Louis Ulrich describes a sandpaper disc loading device that includes a planar support plate from which a plurality of dowels extends in corresponding alignment with the holes in a sanding disc and platen. A disk is inserted over the dowels with the abrasive side toward the support plate and the dowels advance through the platen holes until the back side of the disk engages the surface of the platen. The invention is described as a self-standing device capable of holding multiple sanding discs easing the ability to align the disc to the paper by sliding all of the dowels into the platen at once. However, in use it is critical to maintain the support plate and disk in a parallel orientation to the surface of the platen so the entire disk engages the surface at the same time or proper alignment will not be achieved. This orientation is difficult to maintain unless the device is advanced into the sander from below such that gravity maintains the disk in contract with the support plate. Consequently, insertion of the dowels into the holes of the platen is made more difficult because the holes are obscured from the operator's view on the underside of the sander. Further, the Ulrich invention cannot be used with the sander resting on a bench or other support. Not surprisingly, the Ulrich invention has not been adopted in the marketplace.

SUMMARY OF THE INVENTION

It is, therefore, an object of the present invention to provide a tool for repeatably applying a sanding disk to the platen of a sander with proper alignment between the dust collection holes of the platen and the corresponding holes in the sanding disk.

It is another object of the present invention to provide a tool that allows the disc to be positively secured to the tool such that the disk can be applied to the sander platen in any orientation.

It is another object of the present invention to provide a simple to use tool that is easily and inexpensively manufactured.

It is yet another object of the present invention to provide a tool that is portable and easily kept at the ready for use in a jobsite or other remote location.

And it is another object of the present invention to provide a tool that is adjustable to be used with sanders and disks of varying design.

According to the present invention, the above-described and other objects are accomplished by a sanding disk alignment tool having a base member with at least two pins extending from a surface, the pins sized and positioned for cooperative insertion into the pluralities of dust collection holes in the disk and platen. In a preferred embodiment, the base member is a longitudinal element having a longitudinal edge from which the pins extend. The length of the base member is determined as a function of the hole spacing while the cross-sectional width of the base member is a function of the diameter of the sanding disk. The longitudinal edge is preferably radiused to facilitate bending of the sanding disk around the tool without creasing or otherwise damaging the abrasive surface. In certain embodiments the distance between the pins and/or the set of operative pins is selectively variable to permit use of the tool with sanders having differing platen hole patterns. In certain other embodiments the base member is a flexible planar element with multiple pins in a linear arrangement extending from a single side.

The method of using the disclosed invention includes the steps of inserting the pins through two of the dust collection holes in the sanding disk from the abrasive side, bending the sanding disk around the tool, inserting the pins into through two of the plurality of dust collection holes in the sander platen and advancing the tool and disk to engage the platen. Once initially engaged to the platen, the bend in the disk is released and the sides of the disk are laid down onto and adhered to the platen, after which the tool is removed.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects, features, and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments and certain modifications thereof when taken together with the accompanying drawings in which:

FIG. 1 is perspective view of a tool according to the present invention.

FIG. 2 is an end view of a tool according to the present invention.

FIG. 3 is a section view of a tool according to the present invention.

FIG. 4 is a perspective view of a tool according to the present invention with a sanding disk loaded for use.

FIG. 5 is a perspective view of a tool according to the present invention loaded with a sanding disk and mated in cooperative alignment with a sander.

FIG. 6 is a perspective view of an alternate embodiment of the present invention.

FIG. 7 is a perspective view of a second alternate embodiment of the present invention.

FIG. 8 is a perspective view of a third alternate embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the exemplary embodiment illustrated in the drawings and described below. The embodiment disclosed is not intended to be exhaustive or limit the invention to the precise form disclosed in the following detailed description. Rather, the embodiment is chosen and described so that others skilled in the art may utilize its teachings. It will be understood that no limitation of the scope of the invention is thereby intended. The invention includes any alterations and modifications in the illustrated device, the methods of operation, and further applications of the principles of the invention which would normally occur to one skilled in the art to which the invention relates. Of specific note, while the invention is described and claimed with respect to use with a sanding disk, one skilled in the art will recognize that the teachings of the invention are equally applicable to a non-circular flexible coated abrasives. As such, the term sanding disk should not be construed to be limited to purely circular forms.

With reference to FIGS. 1 and 2, a preferred embodiment of a sanding disk alignment tool 10 according to the present invention is depicted including a base member 12. The base member 12 is a linear member having an upper edge 14 and a lower edge 16. The length of the base member 12 is sufficient to properly position the pins 20 of the invention for cooperative engagement with the dust collection holes H of the platen P of a sander S, typically a random orbital sander, as will be described below. In a preferred embodiment the length of the base member is approximately 75 mm (3 inches) but it will be recognized by one skilled in the art that the length will vary in cooperation with the dimensions of the sander platen with which it is to be used. The cross-sectional width W (see FIG. 3) of the base member 12 is significantly less than the length and is selected as a function of the diameter and material properties of the sanding disk A with which it is to be used in order to permit the desired bending of the disk without damage to the disk's abrasive surface.

In a preferred embodiment, the base member 12 is approximately 12.5% of the diameter of the sanding disk such that, if intended for use with a 127 mm (5″) disk, the width W will be approximately 16 mm (⅝″). The cross-sectional width of the longitudinal base member 12 may preferably be up to 40% of the diameter of the disk, with the best results achieved where the base member 12 is not more than 25% of the diameter of the disk. If intended for use with a 127 mm (5″) disk, the cross-sectional width may thus preferably be up to 51 mm (2.0″) and more preferably up to 32 mm (1.25″). The lower bound of width is a limited only by the material properties of the material from which the base member 12 is constructed but it will be understood that below a certain minimum which varies depending on the material properties of the sanding disk, further reducing the width of the base member will not further reduce the radius of curvature of the disk and increases rather than decreases the risk of creasing or over-bending the sanding disk. At the opposite end of the scale, if the base member 12 is beyond 40% of disk diameter in cross-sectional width then the base member 12 is no longer considered linear unless the lower edge 16 is radiused, as described below.

In the preferred embodiment of FIGS. 1 and 2, two posts or pins 20 extend from the lower edge 16 of the base member 12 at or near the ends of the longitudinal member as shown. It should be observed that relative terms of position such as “upper” and “lower” are used in this application to described the invention as depicted in the figures or otherwise manipulated or described and are not intended to be limiting. In use, the device may be held such that the elements are positioned in any direction relative to one another. The pins 20 are coplanar with the edge 16 and extend in parallel alignment with one another. Pins 20 are positioned a distance D equal to the distance between two dust collection holes H, H′ in the sander platen/sanding disk with which it is to be used. Preferably, where an even number of holes H are provided in a radial orientation around the center of the disk/platen (as in FIG. 4), the distance D is selected as between two holes H aligned on a diameter of the disk/platen. In such case, where a center dust collection hole is provided in the disk/platen, a third pin 20 may be provided for cooperative insertion therein. Where an odd number of holes H are radially positioned about a center of the disk/platen such that no two holes are aligned on a diameter, the distance D is preferably selected as between two holes H as close to opposite one another about the center as possible. Where an odd number of holes H are radially positioned about a center of the disk/platen but a center hole is also provided, D may preferably be selected between any radial hole and the center hole.

The pins 20 are formed for cooperative insertion in the holes H of the sander platen P. Most commonly the holes H and thus the pins P are circular in cross section. The diameter of the pins 20 is selected for snug insertion into the holes of the platen such that the pins can be easily inserted or removed but have little or no lateral play within the holes of the platen when fully inserted. The terms “diameter” and “radius” as used herein are not limited to their respective ordinary geometric meanings relative to a circle but rather include equivalent dimensions of non-circular forms such as, for example, the length and/or width a corresponding rectilinear pin or rectangular sanding “disk”. In a preferred embodiment the pins 20 are approximately 10 mm (⅜″) in diameter for snug insertion into holes of H of a commonly utilized size. The distal ends of the pins 20 may be tapered or rounded to facilitate insertion into the holes of the platen. The length of the pins 20 need only be sufficient to be fully inserted and seated within the holes of the platen and are short enough to permit them to be advanced entirely into the holes of the platen such that the lower edge 16 engages the surface of the platen. In a preferred embodiment the pins 20 are 13 mm (½″) in length.

A handle 30 is provided from the upper edge 14 of the base member 12. In a preferred embodiment the handle 30 is a generally planar element within the plane of the longitudinal base member 12, as depicted, and has a length sufficient such that the distance from the lower edge 16 to the distal end of the handle 30 is substantially equal to or greater than the radius of the sanding disc with which it is intended to be used. A handle 30 is substantially equal to the radius of the sanding disc if a user gripping the tool as in FIG. 4 is able to grip the handle and the disk between the thumb and forefinger. The handle 30 is preferably centered on the longitudinal base member 12 between the pins 20 and in certain embodiments may extend the entire length of the base member 12, although this need not be the case. In certain other embodiments the handle 30 may be integral with the base member 12 such that the base member 12 and handle 30 together form a unitary, planar or monolithic element and such is included within the term longitudinal base member as used herein. A hole may be provided through the handle 30 to secure the handle as by tying to an apron by a string.

With specific reference to FIG. 3, the lower edge 16 of the longitudinal base member 12 is preferably radiused (arcuate) with a radius R such that a sanding disk engaged on or to the tool and bent around the lower edge 16 for loading onto the platen of a sander will not be creased or damaged. The radius need not be continuous or of a single dimension and is preferably from 20% to 100% of the diameter of the disk with which it is intended to be used in order to provide a smooth curvature to back the disk without damage when loaded onto the tool. In a preferred embodiment, the radius R of the lower edge 16 of a tool for use with a 127 mm (5″) disk is 76 mm (3″), but may be anywhere from 55 mm to 127 mm (2″ to 5″). There is no upper bound on the radius R which will eventually converge on a rectilinear lower surface if taken to the extreme, but the practical upper bound of the radius R is two times the diameter of the sanding disk, after which the benefits of radiusing the surface are de minimus.

In alternate embodiments of the present invention, the lower edge 16 of the longitudinal member 12 may be formed as a sector of a regular pentagon, hexagon or octagon, may be rectangular (with or without rounded or individually radiused edges/corners) or triangular (i.e., tapered substantially to a point or small radius) and such is included within the term radiused.

Where a lower edge 16 is radiused, the cross-sectional width of the base member 12 may be increased to as much as 85% of the diameter of the sanding disk and yet still be within the definition of the term linear as used herein. At a width up to 85% of the diameter of the disk, the arcuate surface provided by the radius supports the disk and facilitates bending. In this situation, the cross-sectional width of the base member can be increased within the radius of the arcuate surface without impeding the ability of the disk to curve or bend as described below. That is, radiusing the lower edge 16 facilitates curvature of the loaded sanding disk in the same manner as a substantially thinner base member 12 with a rectilinear lower edge.

By way of example only, the base member of a tool according to an embodiment of the present invention for use with a 127 mm (5″) disk could have a cross-sectional width of only 51 mm (2″) where a rectilinear cross section is provided but a cross sectional width of up to 108 mm (4.25″) if the lower surface is radiused. At this maximum width and with a 127 mm (5″) radius (i.e., 100% of the disk diameter) on the arcuate lower edge, the lateral margins of the base member 12 are more than 15 mm (0.6″) from the surface of the platen when the apex of the radiused lower surface is on the surface of the platen such that only the narrow strip of the adhering surface of the disk along the apex interact with the surface of the platen. Alignment of the disk with the surface of the platen is simplified because only that limited portion of the adhering surface need be aligned and engaged with the surface prior to releasing the wings of the disk as described below.

With reference to FIGS. 4 and 5, a first step in using a tool 10 according to the present invention is to load an abrasive sanding disk A by inserting the pins 20 through the appropriate holes H′ of the sanding disk from the abrasive side. With the pins 20 through the holes H′ and the base member 12 advanced to or near the abrasive surface of the disk, the sides or wings of the disk extending laterally away from the longitudinal member 12 are bent backward to or toward the handle 30 (around the tool), as best seen in FIG. 5, and held in this position by the user. In this position, the lower edge 16 of the longitudinal member 12 is engaged to the abrasive side of the disk and the disk is curved or bent around the lower edge 16 without creasing. Where the lower edge 16 is radiused, less care is required of the user to ensure that the disk does not crease at the bend line as the radiused edge distributes the bending of the disk around the entirety of the curvature. Where the lower edge 16 is rectilinear, some care is required of the user to ensure that disk A is not too tightly curved and the base member 12 too forcefully pressed against the abrasive surface that a crease develops where the rectilinear corners engage the disk. Radiused or not, the user will be able to maintain the disk and tool in this orientation with one hand while aligning the pins 20 with the holes of the platen of a sander held inverted in the opposite hand as depicted in FIG. 4. The tool is advanced toward the platen, led by the apex of the curve (typically, the centerline of the disk) such that it is only necessary to align the tool with the surface of the platen along that centerline (i.e., in one dimension, rather than in two dimensions as is required if the disk is advanced toward the surface of the platen in a planar configuration). When the pins 20 have been fully advanced into the holes H (FIG. 5) such that the portion of the outside surface of the disk along the lower side 16 of the longitudinal member 12 is engaged to the surface of the platen, the wings of the disk are released and folded down onto the platen where they are affixed for use by the PSA or hook-and-loop fastener, as the case may be. The tool is then removed and the disk is left with proper alignment between holes H and H′. This operation is easily accomplished because the tool and the underside of the platen can be maintained in full view of the user during the entire operation, with the “wings” of the disk held back and out of the way of the users view.

In its simplest and, perhaps, preferred form, the tool 10 of the present invention is made as a single unit formed of suitable material such as plastic (ABS, polystyrene, PVC, polycarbonate, polyurethane), wood or metal. Injection molded single part plastic construction may provide the most economical construction. However, unitary construction is limited in as much as the distance D and pin 20 diameter are fixed such that a given tool 10 is suitable for use with only a single sander platen dust extraction hole pattern. With reference to FIG. 7, an alternate embodiment of a tool 100 according to the present invention is depicted in which multiple pin configurations are possible. Tool 100 is provided with a longitudinal base member 112 substantially as described above with respect to base member 12 except that the base member 112 is selectively rotatable about its longitudinal axis X with respect to the handle 130. Additionally, two sets of pins 120 and 120′ are provided, one each on the upper and lower sides 114, 116 of the base member 112 such that the diameter of the pins 120, 120′ and distance D between them corresponds to a different platen dust collection hole pattern. The operative set of pins 120, 120′ is selected by rotating the longitudinal base member 112 relative to the handle 130 and securing it in place such that the desired set of pins 120, 120′ extends from the longitudinal member opposite the handle. The set of pins 120, 120′ not in use remains out-of-the way beside the handle 130 and does not impede operation. Various other variable pin constructions are envisioned. Such alternatives include pins moveable between multiple sockets in the lower side of the longitudinal member and exchangeable with alternate pins of different diameter. Another alternative embodiment 100 of variable pin configuration depicted in FIG. 7 permits one or both portions 12A, 12B of the longitudinal base member to selectively slide longitudinally relative to one another to permit a variable distance D.

With reference to FIG. 8, another alternate embodiment of a tool 200 according to the present invention is depicted. Tool 200 is comprised of a planar base member 212, preferably circular in form and having a diameter substantially equal to that of the sanding disk with which it is intended to be used. Planar base member 212 is preferably constructed of a strong, lightweight polymer that is flexible in sheet form such as, for example, acrylic, polyethylene, polycarbonate, or polyurethane. Alternately, planar base member 212 the may be formed of a rigid sheet plastic bent or bowed and fixed into a curved shape that resembles a traditional hard taco shell. A pair of pins 220 substantially similar to pins 20 are provided extending from one side of the planar base member 212. Pins 220 are preferably situated symmetrically with respect to the center of the preferably circular planar member and are positioned and sized for cooperative insertion into the dust extraction holes H of a sander platen as described above with respect to pins 20 of the previously described embodiment 10. Where the palnar base is formed from a rigid sheet, the pins 220 are situated on the outside surface of the shell along the apex of the curve.

In use, an abrasive disk A is placed abrasive side down on the preferably flexible planar member such that the pins 212 extend through the cooperatively positioned holes H′ of the disk A. The flexible planar member 212 and disk A are then together curled or curved backward (in a direction opposite the side of the planar member 212 from which the pins 220 extend) along a line running through the two pins 212 until they approach or meet each other such that the pins 212 are extended from the apex of the curve for easy insertion into holes H as described above. Once fully inserted the disk A is affixed in proper alignment on the platen and the tool 200 is removed, also as described above.

Having now fully set forth the preferred embodiment and certain modifications of the concept underlying the present invention, various other embodiments as well as certain variations and modifications of the embodiments herein shown and described will obviously occur to those skilled in the art upon becoming familiar with said underlying concept. It is to be understood, therefore, that the invention may be practiced otherwise than as specifically set forth in the appended claims. 

What is claimed is:
 1. A tool for aligning a sanding disk of diameter D with a sander platen having a plurality of dust collection holes, the tool comprising a longitudinal member having an upper longitudinal edge and an opposing lower longitudinal edge, and at least two pins extending from said lower longitudinal edge, said pins positioned along said lower longitudinal edge at a distance d from one another for cooperative insertion into said dust collection holes.
 2. The tool of claim 1, wherein said longitudinal member has a cross-sectional width up to and inclusive of 40% of said diameter D.
 3. The tool of claim 2, wherein said longitudinal member has a cross-sectional width up to and inclusive of 25% of said diameter D.
 4. The tool of claim 1, wherein said lower longitudinal edge is radiused.
 5. The tool of claim 4, wherein said longitudinal member has a cross-sectional width up to and inclusive of 85% of said diameter D.
 6. The tool of claim 4, wherein said radiused lower longitudinal edge has a radius of not more than two times said diameter D.
 7. The tool of claim 6, wherein said radiused lower longitudinal edge has a radius of from 20% to 100% of said diameter D.
 8. The tool of claim 1, further comprising a handle extending from said upper longitudinal edge.
 9. The tool of claim 8, wherein said handle extends a distance from said lower edge substantially greater than or equal to half of said diameter D.
 10. The tool of claim 8, further comprising at least two pins extending said upper longitudinal edge, and wherein said longitudinal member is rotatably affixed to said handle and adapted for rotation about a longitudinal axis.
 11. The tool of claim 8, wherein said longitudinal member is further comprised of a first portion and a second portion, wherein said first portion is selectively slideable along a longitudinal axis of said longitudinal member relative to said second portion, where by said distance d is selectively variable.
 12. The tool of claim 1, wherein said distance d is selectively variable.
 13. A method of aligning and applying a sanding disk having a plurality of dust collection holes there through to a sander platen having a cooperative plurality of dust collection holes, comprising the steps of providing an alignment tool comprising a base member having at least two pins extending from a surface thereof, said pins sized and positioned for cooperative insertion into said pluralities of dust collection holes, inserting said at least two pins through at least two of said plurality of dust collection holes in said sanding disk from an abrasive side of said disk, bending said sanding disk around said tool along a line through two of said at least two pins, inserting said at least two pins into at least two of said plurality of dust collection holes in said sander platen and advancing said tool toward said platen until a portion of said disk engages said platen, releasing and unbending said sanding disk until said disk fully engages said platen, withdrawing said tool from said pluralities of plurality of dust collection holes.
 14. The method of claim 13 wherein said base member of said alignment tool comprises a longitudinal member having a lower longitudinal edge from which said at least two pins extend, and wherein said bending step further comprises bending said sanding disk about said longitudinal edge.
 15. The method of claim 13 wherein said base member of said alignment tool comprises a flexible planar member, and wherein said bending step further comprises cooperatively bending said flexible planar member.
 16. A tool for aligning a sanding disk having a diameter D with a sander platen having a plurality of dust collection holes, the tool comprising a curved surface, and at least two pins extending from said curved surface for cooperative insertion into said dust collection holes, said pins aligned along an apex of a curve of said surface.
 17. The tool of claim 16 wherein said curved surface is flexible.
 18. The tool of claim 16 wherein said curved surface is rigid.
 19. The tool of claim 18 wherein a radius of curvature of said curve does not exceed 1.5 time said diameter D. 